In a nutshell - really, really useful. These actions give some great effects and help you quickly and easily reach the desired effect within Photoshop. I love using Photoshop, but it can be a daunting prospect at times, the actions make it so much easier. They are easy to adapt to your individual taste by simply changing the opacity of the newly-created layer, and pop-up instructions appear to help further in the process. Once you know a little about layers and layer masks you can great results.